Ideal humidity meter for applications up to 100% Relative Humidity. This precision hand-held thermo/hygrometer is ideal for measuring and monitoring ambient and dew point temperatures and relative humidity in a wide range of professional and industrial applications. Dual readout LCD displays in F or C. Temperature range/accuracy: -4 to 122F (-20 to 50C)/1.8F (1C), Humidity range/accuracy: 0 to 100%RH /3% , Response time: 60 seconds, Power source: Two "AAA" batteries (included).